Plant profiles > Muehlenbeckia
Family : Polygonaceae
Resistance is an attribute that this genus demonstrates admirably; whether standing up in the face of biting, salt-laden winds on our coastlines, or weaving their way through the exposed surface of braided riverbeds. Muehlenbeckia are amongst the most adaptable of New Zealand's native plants, and as a result are a common feature of many of our landscapes.
New Zealand has five species of Muehlenbeckia, most of which exhibit a climbing or sprawling growth habit. The exception amongst these is the densely shrubby Muehlenbeckia astonii, although M. complexa can get shaped by harsh winds into forms that seem densely shrubby1.
The two lower-growing species, M. axillaris and M. ephedroides, are most often seen carpeting the ground in rocky and gravelly habitats (like the mountain slope through which M. axillaris creeps, in the picture to the right). In contrast , the more vigorous species, M. australis and M. complexa can (in stable, sheltered conditions) be quite overwhelming in their growth, sometimes overrunning shrubs or small trees.
A feature shared by all of our Muehlenbeckia spp. is the appearance of beautiful small fruits, following flowering. The usually translucent outer parts of these fruits are fleshy 'tepals' (a type of floral part, like an undifferentiated petal or sepal), which contain a hard black fruit (called an achene) at their centre. It is worth observing these fruits up close, especially on the more diminutive species - upon which the fruits are obviously, by comparison, more conspicuous.
Our species of Muehlenbeckia play an important ecological role as hosts for our native copper butterflies. These beautiful insects (of which New Zealand has several species) occupy a range of habitats, from coastal sand dunes to the mountains.
Muehlenbeckia spp. are known collectively as pohuehue. The genus derives its intriguing name from a notable physician from Alsace, H. G. Muehlenbeck, who worked on mosses and fungi2.
Muehlenbeckia ephedroides
Leafless pohuehue
Of the 'freaks and geeks' within the New Zealand flora, this little creeper is one of the most delightfully weird on offer. It sends out a network of iridescent, spidery stems, that lend the plant an appearance of rushes flattened to the ground, or some kind of bizarre bird's nest. Its appeal does not just lie in its curiosity value, but also in the sculptural effect created by the bright greyish-purple stems, especially when they are allowed to trail over walls or slopes.
Muehlenbeckia ephedroides is a classic example of the radical difference between how a plant looks within nature, and the form that it exhibits within cultivation. Plants viewed in the wild, such as those growing in the braided riverbed of the Cass River (shown to the right), often display the aforementioned 'bird's nest' character, due to the harshness of their habitat, and the nature of the rocks through which they grow. However, plants grown within garden situations usually assume the more distinctive, and attractive, rush-like form that is evident in the image below.
The leafless pohuehue naturally occurs in a range of sandy and gravelly habitats, such as braided riverbeds or bouldery beaches (like at Te Awanga, in Hawkes Bay). It is found in a number of scattered sites (mostly coastal) in the North Island, whereas it is far more widespread in dry eastern regions of the South Island. M. ephedroides is officially listed as 'Declining' in the wild, a threat ranking that reflects in part its preference for habitats that can come under pressure from human activities.
The kinds of dry, exposed ecologies to which it is adapted also host a number of other unusual, almost leafless plants, including the leafless Clematis (C. afoliata) and two strange shrubby daisies (Helichrysum depressum and the lianoid H. dimorphum), and a creeping broom, Carmichaelia appressa.
As can be seen from the lowermost photo of M. ephedroides, it is not totally leafless, and can in fact bear a relatively high number of leaves - when growing in sheltered or slightly shaded conditions. The leaves, however, are the same colour as the greyish stems, and do not register as being separate (to the eye). When planted within gardens, M. ephedroides should be given a well-drained, open position. It is surprisingly amenable to cultivation as far north as Auckland, as long it is not placed in competition with other plants.
Leafless pohuehue receives its specific epithet from a perceived similarity to members of Ephedra (shrubby horsetail), a genus of rush-like plants that occurs throughout much of the Old World3.
Footnotes
- If, however, the variable of wind is removed, the plant returns to its natural lianoid growth habit.
- As stated within 'Meanings and origins of botanical names of New Zealand plants (Taylor, M. 2002. Auckland Botanical Society Bulletin 26.).
- As well as North and South America.